The SitePoint Forums have moved.

You can now find them here.
This forum is now closed to new posts, but you can browse existing content.
You can find out more information about the move and how to open a new account (if necessary) here.
If you get stuck you can get support by emailing forums@sitepoint.com

If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

and this is fine if on the page there is only one request, as they create a global var XMLHttpRequest.

However, I thought that it could happen that there are many requests at once (like if the user, while it's waiting for the first request to be completed, continues doing stuff, starting another request).